Tensioning means for loom let-off beams



NOW, 26, 1935. R M TAYLOR G MEANS FOR LOOM LET-OFF BEAMS TENSIONIN FiledAug. 26, 1933 2- Sheets-Sheet l New 26 135. R. M. TAYLOR 2M2 TENSIONINGMEANS FOR LOOM LET-OFF BEAMS Filed Aug. 26, 1935 2 Sheets-Sheet 2 72.17Taylor Patented Nov. 26, 1935 UNlTED STATES PATENT OFFICE TENSIONINGMEANS FOR LOOM LET-OFF BEAMS 12 Claims.

This invention relates to improvements in the let-01f beams of looms andparticularly to means for keeping a constant and uniform tension on thewarp, the mechanism being particularly adapted for use in silk looms,though it may be also used on cotton and woolen looms.

Various friction creating or tension creating means have been devisedand used for this purpose, but the tensioning means usually usedconsists of a rope wound a plurality of times around a head of the warpbeam, there being weights on the ends of the rope, thus creating afriction, resisting rotation of the left-off beam or warp beam and thuskeeping a constant tension upon the ends. Tensioning means of thischaracter are open to many objections. The tension upon the first lap ofthe rope above referred to, which first lap is connected to a weightedlever, is very great and it is this very great pressure which causes itto grip the drum or head of the beam, this causing an unevendistribution of tension. Even so, this friction warp tension caused bythe use of a rope wound around the drum, has proved the mostsatisfactory of all of the other methods proposed. However, the loomfixer must constantly take the ropes off every few days and rub themwith flake graphite or some other lubricating subsbtance and even whenthis is done, it is impossible to make these ropes slide evenly on heavyweighted warps during damp weather.

Furthermore, the rope tension contacts with the head only at one pointin the circumference of the rope and when the contact between the "ropeand the beam head is about three-sixteenths of an inch wide, then lessthan six square inches of rope is in contact with a ten inch warp headfor the entire three laps of the rope and thus very great pressure mustbe placed upon the rope or a very great pull in order to securesufficient friction.

The general object of the present invention is to provide a frictiontensioning device for let-off beams which will provide for a great deallarger area of braking surface or tensioning surface and which is notopen to the odjections to which the rope tensioning means heretoforedescribed is open.

A further object is to provide a structure of this character embodying abrake band located at each end of the beam and engaging the headsthereof, each brake band having a relatively large area of contact withthe corresponding head a and provide positively acting means for causingthe release of tension on the brake band as soon as this brake bandstarts to move with the beam head and further provide for this purpose abraking arm operatively connected as will be described to opposite endsof the brake band and connected to a weight urging the brake bandclosed, the 5 brake band as a whole being operatively connected toanother weight acting to rotate the brake band in a direction reverse tothe direction of rotation of the beam head, and so connected to the armthat as soon as the brake band starts to rotate with the beam head, thepull on the brake arm will be positively released and the tension on thebrake band decreased.

Other objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawings, Wherein:

Figure 1 is a. side elevation partly in section of a let-off beam withmy frictional braking mechanism applied thereto and showing the brake 0applied;

Figure 2 is a like view to Figure 1 and showing in a greatly exaggeratedmanner the action taking place when the brake is released;

Figure 3 is a rear elevation of the beam and its connections to theweight supporting rod;

Figure 4 is a front elevation of my mechanism.

Referring to these drawings, ID designates a warp beam which isordinarily of wood and has a length of approximately five feet. Mountedupon the ends of this warp beam are the usual heads H, these heads beingof iron and having a width between the flanges l2 of approximately 2%inches. The frame supporting this beam has not been illustrated but thebeam rotates around an axis formed by the warp bracket pins l3.

Disposed to surround each of the heads and fit between the flanges I2 isa brake band designated generally I4 which is preferably formed of wovenmaterial which is chemically treated so that weather conditions will notaffect it. Two plies of this woven material extend entirely around thebeam head H and one ply of the woven material extends partly around thebeam head and then extends downwardly therefrom. The plies may beriveted or otherwise attached to each other at any desired or necessarypoints. Attached to the extremities of the band M are the steel clips l5and I6, these preferably being riveted to the ends of the band. The clipI6 is bifurcated and disposed within this bifurcation and pivoted to theclip at I! is a braking arm 18. This braking arm is about eight inchesin length under ordinary circumstances. The clip I5 is provided with aneye l9 and connected which in turn is connected to the eye IQ of theuponthe clip [5. It will thus be obvious that when the lever i8 ispulled downward, the brake band will be tightened up upon the head andthat when it is moved in the other direction, the brake band will beloosened.

Disposed below each head of the warp beam H is a supporting framedesignated 2! which is held rigidly to the fioor by screws 22 or anyother suitablemanner. This frame is approximately nine inches from frontto rear and approximately thirteen inches in height at its rear and sayten inches in height at its forward end. Pivotally mounted upon thisframe is a lever 22, the upper end of the lever being somewhat nearer tothe pivot than the lower end of the lever, though this is a matter ofadjustment and connected to the upper end of this lever is a chain 23which in turn is connected to the free end of the arm or lever H! bymeans of the link 24. Also connected to the upper end of the lever 22 asby means of the hook 25 is a chain 26 which passes over a pulley 2!carried by the frame, this chain at its lower end supporting a weight 28which may be from five to fifteen pounds depending. upon thecircumstances. It will be seen that this weight tends to pull inward orrearward the upper end of the lever 22 and that this pulls downward uponthe brake arm l8. Thus the weight 28 tends to apply the brake band.

The outerply I la of the brake band M depends over the rear of the brakeband and at its lower end it supports a transverse weight bar 29carrying a plurality of weights 30, the number of weights carrieddepending upon the number of warp ends used and the tension desired tobe placed upon the warp ends 7 Engaged with the ends of the rods 26 arechains 3!, these chains extending downward parallel to the rear of theframe 2|, passing beneath the pulley 32, and being connected to a hook33 carried by the lower end of the lever 22.

It is to be understood that at each end of thebeam, that is, upon eachhead of the beam, there is a brake band 14 with its lever l8: and

that each lever I8 is connected to a lever 22. urged rearward by meansof a weight 28, both of these levers at their lower ends being connectedby a chain 3| to the weight bar 29.

The operation of this mechanism is as follows:-

The warp beam with its heads is being pulled in the direction of thearrow in Figure 1 by the warp threads or ends. -If there was no brakebeam, the beam would move freely and no tension would be placed on thewarp threads. The brake band I4, therefore, when it is tightened exertsfrictional resistance to the rotation of the beam H and tends torotateas a consequence with the beam against the action of the weights 3% onthe weight bar 29. If the'brake bands were at all times tightly engagedwith the beam heads, the rotation of the beam would act to lift theweights 30. It is, therefore, necessary that the brake band shall bereleased intermittently at very short intervals so that the brake bandhas a sliding engagement with the beam head. Q'Ihis is secured by themechanism which I have described. Ordinarily the weights 28 exerting apull upon the arms l8 will draw the brakes tightly against the heads butas soon as the brake bands shift with the beam in the direction of thearrow, the chain 3| is pulled upward by the upward movement of theweight bar and this draws the lower end of the lever 22 inward relaxingthe tension on the chains 23 and relaxing the pull on the arms l8, thusslackening the pressure of the brakes. As soon as the brake pressure hasbeen relieved, the weights on the weight bar again act to urge the brakebands in a counter-clockwise direction, thus again permitting theweights 28 to apply the brakes and again causing a release of the brakesas soon as the brake bands move with the beam.

It will be seen that, in mymechanism, leasing movement is positive inits action. The moment that the band it rotates with the beam head, thepressure is instantly released. In my invention, the pressure producingthe frictional resistance to a rotation of the beam heads is spread overa surface of more than twenty square inches, using the band two andone-quarter inches wide and lapping around a ten inch warp beam head.

It will, of course, be understood, however, that my invention is capableof use on a six inch, ten inch, eight inch or beam head of any size andthat it is equally applicable to a beam having any desired length. It isbecause of the positive releasing action which I have provided that mymechanism is particularly adapted to broad silk looms. This releasingmechanism has been found in practice to work very steadily and gives amuch more even tension than any mechanical warp let-oir or old fashionedweighted rope friction that I have ever seen.

It will be seen that with this invention, if the tension is exactlyright, there will be a constant frictional engagement of a predeterminedamount between the brake band and the warp beam resisting to apredetermined degree the rotation of the warp beam but that if thisbrake band starts to clamp too tightly and move with the warp beam, itis promptly released and the tension on the brake band and thefrictional engagement with the beam head relieved.

While I have illustrated certain details of construction and certainarrangements of parts which I have found to be thoroughly effective forthe purpose intended, I do not wish to be limited to these as manychanges might be made without departing from the spirit of the inventionas defined in the appended claims.

It is to be understood that in Figure 2, I have illustrated in a greatlyexaggerated manner the action taking place when the weight 30 movesupward and releases the brake.

' I claim:-

1. A braking mechanism of the character described including a rotatablehead, a brake band embracing the head, an arm pivoted to one end of thebrake band and having an operative con nection adjacent said pivot totheother end of the brake band, a weight urging said arm in a the re- 2.The combination with a let-01f beam having a head, of a brake bandembracing the head, an arm pivoted to one end of the brake band, a

connection between said arm and the opposite end of the brake band, saidconnection being disposed between the pivot of the arm and the free endthereof, a weight carried by and urging the arm in a direction totighten the brake band on the head, and means entirely independent ofthe brake band and arm acting automatically immediately that the bandmoves with the head to relieve the tension on the arm of the weightcarried thereby to thereby relieve the tension on the brake band.

3. The combination with a let-oif beam having a head, of a brake bandembracing the head, an arm pivoted at one end of the band, a connectionadjacent the pivot of the arm to the opposite end of the band, a leverpivoted intermediate its ends and connected at one end to the free endof the arm, a weight operatively connected to the last named end of thelever and acting to draw the lever in a direction to cause the arm totighten the brake band, and an operative connection from the brake bandto the other end of said lever acting to retract the last named end ofthe lever, lift the weight and relieve the tension on the brake bandwhen the brake band moves in the same direction as the head.

4. The combination with a let-off beam having a head, of a brake bandembracing the head, an arm pivoted at one end of the band, a connectionadjacent the pivot of the arm to the opposite end of the band, a leverpivoted intermediate its ends and connected at one end to the free endof the arm, a weight operatively connected to the last named end of thelever and acting to draw the lever in a direction to cause the arm totighten the brake band, a weighted element, an operative connection fromthe weighted element to the brake band and urging the brake band in adirection reverse to the direction of movement of the head, and apositive connection from said weighted element to the end of said leveropposite from its point of attachment to the arm.

5. The combination with a let-off beam having a head, of a brake bandembracing the head, an arm pivoted to one end of the brake band, aconnection from said arm to the other end of the brake band and locatedadjacent the pivotal point of the arm, a lever pivotally supported belowthe arm and having its upper end operatively connected thereto, a weightconnected to the upper end of the lever and urging the lever in adirection to place a strain upon the arm to tension the brake band onthe head, a weighted element, a connection from said weighted element tothe brake band, the weighted element acting to urge the brake band in adirection reverse to the direction of rotation of the head, and apositive connection from said weighted element to the lower end of saidlever whereby as the weighted element is drawn upward by the rotation ofthe brake band with the head, the upper end of the lever will be shiftedin a direction to release said arm and relieve tension on the brakeband.

6. The combination with a let-off beam havingheads on its opposite ends,of brake bands embracing one of the heads, an arm pivoted to one end ofeach brake band and having an operative connection to the other end ofeach brake band, a lever pivotally mounted beneath each arm and havingits upper end operatively connected to the free end of the correspondingarm, a weight for each lever urging the upper end of the lever in adirection away from the arm to thus apply the corresponding brake band,a flexible connection attached to each brake band, a weight barsupported by said flexible connections, detachable weights disposed uponsaid bar, said bar and the weights urging both brake bands 5 in adirection reverse to the direction of movement of the heads, and apositive connection between the weight bar and the lower ends of each ofsaid levers acting as the weight bar moves upward to lift the firstnamed weights and relieve strain on the arms and tension on the brakebands.

'7. The combination with a let-off beam having a flanged head, of abrake band composed of a plurality of plies of textile fabric, the brakeband being transversely flat and bearing across its whole width againstthe head, the brake band being interrupted at one point, an arm pivotedto one end of the brake band, an operative connection between the otherend of the brake band and the other adjacent its pivotal point, aweight, a connection from said weight to the free end of the arm, theweight acting to apply the brake, one of said plies of flexible materialextending over the upper face of the brake band and then extendingdownward from a point diametrically opposite the interruption in thebrake band, a weight attached to said depending ply, and an operativeconnection entirely independent of the brake band and arm and extendingfrom said depending ply to the first named weight and acting tolift thefirst named weight and relieve the tension on the arm when the brakeband rotates with the head.

8. In a mechanism of the character described,

a rotatable member, a brake band embracing the rotatable member, an armpivoted at one .end of the brake band, an operative connection betweenthe other end of the brake band and said arm adjacent the pivotal pointthereof, the brake band being free to rotate with the rotatable memberwhen the brake is applied, gravity actuated means operatively engagingsaid free end of the arm and urging the brake to applied position,gravity actuated means resisting the rotation of the brake band with themember, and means entirely independent of the brake band and armoperatively connecting the last named gravity actuated means with thefirst named gravity actuated means acting to lift the first namedgravity actuated means relative to the arm to thereby release the brakearm and relieve the tension on the brake when the second named gravityactuated means is moved upward by a rotation of the brake band with saidmember.

9. The combination with a let off beam having a head, of a brake bandembracing the head, a weight urging the band toward a closed brakeapplying position, gravity actuated means urging the brake band bodilyin a direction reverse to the direction of rotation of the beam, andmeans entirely independent of said weight positively supporting theweight against further downward movement immediately that the band hasmoved a predetermined distance with the head to thereby relieve thetension on the brake band under the action of the first named means whenthe brake band is shifted in the direction of rotation and with thebeam.

10. The combination with a let-off beam having a head, of a brake bandembracing the head, 7 0 an arm pivoted toone end of the brake band, aconnection between said arm and the opposite end of the brake band, saidconnection being disposed between the pivot of the arm and the free endthereof, means urging the arm in a direction to tighten the brake bandon the head and means entirely independent of the arm rendering saidurging means inoperative immediately that the band has moved apredetermined distance with the head to thereby relieve the tension onthe brake band;

11. The combination with a let-off beam having a rotatable head, of abrake band embracing the head, an arm pivoted at one end to one end ofthe brake band and having an operative connection adjacent said pivot tothe other'end of the brake band, a weight urging the arm in a directionto apply the brake band and tighten it upon the rotatable head, a secondweight resisting rotation of the brake band with the rotatable head whenthe brake band is tightened, and means independent of the arm actingautomatically to positively prevent further downward movement of thefirst-named weight and of the arm immediately that the brake band tendsto' move with the rotatable head to thus release the brake band.

12. The combination with a let-oif beam having a head, of a brake bandembracing the head and having its ends spaced apart, a lever pivoted toone end of the brake band and operatively connected adjacent said pivotto the other end of the brake band, a weight operatively connected tosaid lever and normally urging the ends of the brake band toward eachother to tighten the band around the head, means independent of thebrake band and lever automatically relieving the pull of said weight onsaid lever upon an initial movement of the tightened brake band with thehead, and means urging the brake band in a direction reverse to thedirection of movement of the beam and head and acting to shift the brakeband in this reverse direction until the brake band has again tightenedupon the head.

RAY M. TAYLOR. 20 l

